Progress 10/01/23 to 09/30/24
Outputs
PROGRESS REPORT Objectives (from AD-416): Objective 1. Conduct research to develop high yielding sunflower germplasm and inbred lines with adaptation to a wide range of production environments and resistance or tolerance to abiotic and biotic stressors. Subobjective 1A: Investigate genetic basis of Phomopsis resistance and introduce new disease resistance genes from wild sunflower species into cultivated sunflower. Subobjective 1B: Characterize mechanisms of sunflower resistance to Phomopsis stem canker pathogens and responses to necrosis-inducing culture filtrates. Subobjective 1C: Evaluate diverse interspecific germplasm for resistance to Phomopsis, rust, and downy mildew. Subobjective 1D: Develop advanced sunflower inbred line germplasm with novel traits or combinations of agronomically important traits. Objective 2. Conduct research to elucidate the effects of environmental variation on economically important sunflower traits and/or genes related to host plant resistance of insect pests and provision of resources for pollinators such as superior pollen nutrition and nectar quality for use in breeding. Subobjective 2A: Evaluate planting date and hybrid effects on damage by the red sunflower seed weevil and test host plant resistance under extremely high weevil populations. Subobjective 2B: Evaluate plant genetic and environmental effects on nectar and pollen rewards. Approach (from AD-416): Sunflowers are a source of heart-healthy oil and other products with low saturated fats and no trans fats. In farming rotations, sunflower is considered a low-input crop that helps limit problems with weeds or diseases in other crops. However, sunflower growers are challenged to find hybrids that use elite germplasm with proven adaptation to their growing regions, incorporating host plant resistance to the pathogens and insects that reduce average yields and consistency of yields. In particular, increasing problems with Phomopsis stem canker (PSC) and red sunflower seed weevil (RSSW) in the U.S. have not been adequately addressed by a seed industry that has been moving research and breeding out of North America. The proposed research will advance sunflower production by (1) developing genetic markers for resistance to major sunflower diseases, (2) investigating specific mechanisms of resistance to PSC, (3) identifying new sources of genetic resistance to sunflower diseases, (4) evaluating resistance and early-maturity as tools to manage RSSW, (5) examining factors that influence sunflowers� nectar and pollen rewards to pollinating insects (which support crop yields), and (6) combining desired traits to create superior germplasm that is adapted to the major North American growing environments. Success in the Project Plan components will provide improved genetic resources for commercial sunflower breeders, new options for growers to manage biotic and abiotic stresses to their crop, and support a stable, affordable supply of sunflower products to consumers. Subobjective 1A: A single replication of a greenhouse inoculation experiment was carried out to evaluate stem lesion resistance to Diaporthe helianthi for 160 recombinant inbred lines (RILs) derived from a cross between the partially resistant sunflower inbred line HA 378 and the susceptible line HA 89. Mean stem lesion lengths at 7-days post- inoculation exhibited a continuous distribution and ranged from 6mm for the most resistant RIL to 133mm for the most susceptible. Mean stem lesion lengths for the partially resistant parent HA 378 and the susceptible parent HA 89 were 26mm and 83mm, respectively, indicating transgressive segregation consistent with quantitative resistance to Phomopsis stem canker. DNA isolation to facilitate genotyping of the population and subsequent quantitative trait locus mapping is underway and two additional replications of the greenhouse inoculation experiment will be conducted in future years. Subobjective 1B: Characterize mechanisms of sunflower resistance to Phomopsis stem canker pathogens and responses to necrosis-inducing culture filtrates. Greenhouse evaluations of 60 sunflower lines were carried out to identify lines exhibiting petiole transmission resistance to Phomopsis stem canker. Three experimental replications of cut petiole inoculations with D. helianthi isolate L2 were performed in which inoculated plants were evaluated for frequency of stem lesion formation and lesion length at 7- and 14-days post-inoculation. Nine sunflower lines, including two inbred lines and seven open-pollinated plant introduction lines, were significantly more resistant to stem lesion formation after petiole inoculation than the susceptible control with three plant introduction lines exhibiting very strong resistance to transmission of the fungus from the petiole into the stem. Additionally, optimal culture conditions were identified for production of toxic metabolites by D. helianthi. Culturing of D. helianthi isolates in malt broth for 21 days at 20�C resulted in culture filtrates that caused rapid and strong tissue necrosis after infiltration into leaves of the sensitive sunflower inbred line HA 410. Culture filtrates produced under these conditions will be used to evaluate sunflower lines for toxin insensitivity. Subobjective 1C: Evaluate diverse interspecific germplasm for resistance to Phomopsis, rust, and downy mildew. Greenhouse screening of interspecific germplasms for disease resistance was not conducted due to multiple critical vacancies (2 scientists and 1 technician). Subobjective 1D: Develop advanced sunflower inbred line germplasm with novel traits or combinations of agronomically important traits. Over 4, 300 nursery rows of high yield, high oil, disease, insect, and herbicide- resistant sunflower experimental lines were grown in nurseries in Fargo, North Dakota, and Chile, with yield trials of experimental hybrids from these lines also grown at several locations throughout the sunflower growing region, including North Dakota, South Dakota, Minnesota, and Kansas. Of these, HA 490, RHA 491, RHA 492, and HA 497 were identified as novel downy mildew resistant lines with Sclerotinia and Phomopsis resistance, high yield, and high oil content. HA 490 and HA 497 have high oleic acid in the seed oil. The dockets are currently with National Programs Staff. Subobjective 2A: Evaluate planting date and hybrid effects on damage by the red sunflower seed weevil and test host plant resistance under extremely high weevil populations. Field tests with four planting dates and two sunflower hybrids were conducted at three locations in North Dakota and South Dakota. At their peak, populations of adult seed weevils at trial locations were high to extremely high. At two of three sites, early planting reduced seed damage by weevils by 70�80%. Yield and quality (% oil) for early plantings were as good or better than late plantings. A fourth site in North Dakota used artificial infestations of weevils to show a line with host plant resistance (HA 488) provided a consistent advantage at populations as high as 20 times the economic threshold. Repeatability of previous results is being assessed in a second year at each of the three locations with naturally high weevil populations. Subobjective 2B: Evaluate plant genetic and environmental effects on nectar and pollen rewards. The effects of temperature on nectar volume (microliters per floret), concentration (Brix), and sugar composition (percent sucrose) were assessed in seven different sunflower lines grown under different temperatures in plant growth chambers. Though the sunflower nectars varied by line (genetic effect), there were also effects of temperature (environment) and genotype � environment interactions. Though nectar volumes varied five-fold among lines, environment and genotype � environment can obscure these differences, especially under field conditions. Preliminary data on pollen quantity under field conditions shows floret size is a good predictor of pollen within a floret, but that some inbred lines fail to extrude much of the pollen they produce, limiting their value for crop pollination and as forage for wild and managed bees. ACCOMPLISHMENTS 01 Winter behavior and survival of the red sunflower seed weevil. The red sunflower seed weevil is the most serious insect pest of sunflowers in North and South Dakota. Weevil larvae (�grubs�) spend most of the year in the ground until summer, when adults emerge. Survival of larvae through the winter is inconsistent. ARS scientists in Fargo, North Dakota, and colleagues at North Dakota State University observed behavior and tested larval survival under different temperature treatments. Though the soil does not get cold enough to freeze larvae, stress from a week or more of very low temperatures appears to produce enough stress to cause death. This result helps explain the much higher populations in South Dakota and suggests warmer winters may support higher populations of this pest. However, the location of larvae very close to the soil surface means routine farm management, including tillage and herbicide incorporation, can be useful. This information shows a cause of a worsening pest problem but also shows growers, extension personnel and other researchers the value of options other than insecticides, including early-maturing hybrids, to help manage weevil populations. 02 The composition of root-zone microbes in sunflower is inherited and supports resistance to Sclerotinia basal stalk rot. Plants and microbes are known to interact in ways that influence plant health and growth. However, how plant genetics influence the composition of microbes is not well understood. ARS scientists in Fargo, North Dakota, and colleagues at University of Colorado � Boulder showed that sunflower lines help influence the abundance and diversity of microbes around sunflower roots under field conditions. Eliminating microbes in soil using high heat caused sunflower-resistant lines to lose their resistance to Sclerotinia. About five-dozen locations on sunflower chromosomes were shown to influence composition of root-zone microbes and resistance to Sclerotinia. This work shows that microbe communities, influenced by plants, play important roles in defending crops and provides new targets for sunflower breeders to create a disease- resistant crop. 03 Variation in isolates of the Phomopsis stem canker pathogen Diaporthe helianthi. Phomopsis stem canker (PSC) is a major yield-limiting disease affecting sunflower production worldwide that can cause yield losses of up to 50%. This disease is usually caused by the fungus Diaporthe helianthi but can be caused by other Diaporthe species. ARS scientists in Fargo, North Dakota, surveyed PSC in sunflower fields over two years in Minnesota, North Dakota, and South Dakota and isolated the causal fungus from 363 stem lesions (visible diseased areas). D. helianthi was isolated from 93% of the surveyed lesions, while D. gulyae was isolated from 5% of lesions and both D. helianthi and D. gulyae were isolated from four lesions. Additionally, D. caulivora, a soybean pathogen that had not been previously reported to cause Phomopsis stem canker on sunflower in the U.S., was isolated from two PSC lesions collected in Minnesota. Analyses of the D. helianthi isolates indicated populations sampled from the three states were generally genetically similar. Testing of sunflower lines with some resistance to PSC using different D. helianthi isolates showed resistance in most lines was limited to specific isolates. Four sunflower lines with strong resistance to all tested isolates were identified and these lines will be used by sunflower breeders as sources of resistance to PSC.
Impacts
(N/A)
Publications
- Gesch, R.W., Mohammed, Y.A., Walia, M.K., Hulke, B.S., Anderson, J.V. 2022. Double-cropping oilseed sunflower after winter camelina. Industrial Crops and Products. 181. Article 114811. https://doi.org/10.1016/j.indcrop.2022. 114811.
- Qi, L., Seiler, G.J. 2023. Registration of HA-DM15 and HA-DM16 oilseed sunflower germplasms with resistance to sunflower downy mildew. Journal of Plant Registrations. https://doi.org/10.1002/plr2.20325.
- Guojia, M., Xuehui, L., Seiler, G.J., Qi, L. 2023. Registration of HA-R20 and HA-R21 confection sunflower germplasms resistant to rust and downy mildew. Journal of Plant Registrations. https://doi.org/10.1002/plr2.20324.
- Pogoda, C.S., Reinert, S., Talukder, Z.I., Corwin, J., Money, K.L., Collier-Zans, E.C., Underwood, W., Gulya, T.J., Quandt, C., Kane, N., Hulke, B.S., Keepers, K.G., Smart, B. 2023. Heritable differences in abundance of bacterial rhizosphere taxa are correlated with fungal necrotrophic pathogen resistance. Molecular Ecology. https://doi.org/10. 1111/mec.17218.
- Pantzke, S., Rajamohan, A., Ferguson, B., Rinehart, J.P., Prischmann- Voldseth, D.A., Prasifka, J.R. 2024. Development of a degree-day model for adult emergence of the red sunflower seed weevil, Smicronyx fulvus LeConte (Coleoptera: Curculionidae). Journal of Kansas Entomological Society. 97(1) :26-38.
- Underwood, W., Misar, C.G. 2024. Multiple forms of resistance to the Phomopsis stem canker pathogens Diaporthe helianthi and D. gulyae in sunflower. Plant Disease. 108:1704-1749. https://doi.org/10.1094/PDIS-03- 23-0610-RE.
- Prasifka, J.R., Hulke, B.S. 2024. Efficacy of red sunflower seed weevil resistance from inbred line cms HA 488 in single-cross hybrids. Agronomy Journal. 116:2081-2084. https://doi.org/10.1002/agj2.21613.
- Talukder, M.I., Underwood, W., Misar, C.G., Li, Z., Seiler, G.J., Cai, X., Qi, L. 2023. Genetic analysis of basal stalk rot resistance introgressed from wild Helianthus petiolaris into cultivated sunflower (Helianthus annuus L.) using an advanced backcross population. Frontiers in Plant Science. 14. https://doi.org/10.3389/fpls.2023.1278048.
- Sharma Poudel, R., Belay, K., Nelson Jr, B., Brueggeman, R., Underwood, W. 2023. Population and genome-wide association studies of Sclerotinia sclerotiorum isolates collected from diverse host plants throughout the United States. Frontiers in Microbiology. 14. https://doi.org/10.3389/ fmicb.2023.1251003.
- Ferguson, M., Prasifka, J.R., Carroll, M.J., Corby-Harris, V.L., Hoffman, G.D. 2024. Honey bee (Apis mellifera L.) foraging rewards in sunflowers: effect of floral traits on visitation and variation in pollen quality over two consecutive years. Journal of Apicultural Research. https://doi.org/10. 1080/00218839.2024.2364948.
- Gossweiler, A.D., Hulke, B.S., Smart, B. 2024. Survival analysis of freezing stress in the North American native perennial flax, Linum lewisii Pursh. AoBP (Annals of Botany PLANTS). 16(3). Article plae022. https://doi. org/10.1093/aobpla/plae022.
- Glogoza, B., Aldrich-Wolfe, L., Prasifka, J.R., Prischmann-Voldseth, D.A. 2023. Impact of multiple soil microbial inoculants on biomass and biomass allocation on the legume crop field pea (Fabaceae: Pisum sativum L.). Journal of Sustainable Agriculture. 2(3):314-327. https://doi.org/10.1002/ sae2.12060.
- Prasifka, J.R., Portlas, Z.M., Hulke, B.S. 2023. Pollen quantity, but not grain size, is correlated with floret size in in cultivated sunflower, Helianthus annuus L. Plant Genetic Resources. 21(3):269-273. https://doi. org/10.1017/S1479262123000709.
|